Triethylamine → 1-Cyclopropyl-6,8-difluoro-7-(1,5-dioxa-8-azaspiro[5.4]dec-8-yl)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid

Participants

Reaction Steps

A 0.276 g (1.8 mmol) sample of 1,5-dioxa-8-azaspiro[5.4]decane, from Step 2 Example 14, 0.400 g (1.29 mmol) of 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid ethyl ester (preparation described by K. Grohe, et al., DE 3318145, November 1984) and 0.52 mL (3.7 mmol) of triethylamine and 12 mL of pyridine were heated at 65° C. for 48 hours in dry glassware and under dry nitrogen. The solvent was evaporated and the ester purified by chromatography on a silica gel column using as eluant 0.5% methanol in methylene chloride increasing to 2% methanol in methylene chloride. The solvent was removed to afford 0.218 g of the title compound, which was taken to the next step directly.

Provenance & Evidence